Best format for campaign setting books

[Yora]

I've been working on a campaign setting for the last three or four years and have now reached a point where I think I pretty much have all the essential elements designed to make it a complete world that can stand on its own feet.
Now I want to publish it to a larger audience for free. But all the material consists of notes and ideas in my head, which now all need to be written down. And I am still quite unsure how to structure such a document.

It's not a super complex and detailed world like Forgotten Realms, Eberron, Golarion, Planescape, or Legend of the Five Rings. It's probably more like the first versions of Greyhawk and very early Forgotten Realms, Red Tide, or the setting from Dragon Age. Not a big franchise universe, but not a mini-setting either.

Lot's of people have a very high regard for the first edition Grey Box set for Forgotten Realms, and I personally quite like The Savage Frontier supplement for it. Structuring my own setting in such a style might work quite well. But I was really wondering what other people think about good ways to present a new setting.
Have you any preferences for what topics are being covered and how everything is sorted into useful categories?

[Palegreenpants]

It depends, what sort of content-chunks do you have?

[Thinker]

Have you considered releasing it as a wiki instead of as a book?

[Sebastrd]

The FRCS from D&D 3.0 is one of the most highly regarded setting books of which I know. You could start there.

[LibraryOgre]

I'd go with a combination of organizing it by usefulness and size of the chunks.

So, you start with some relatively small chunks that are immediately useful... things like adjustments to standard race and class rules. This makes those portions easy to reference while creating a character ("My ranger has to do what now?"), and also helps convey the tone.

You then go to non-geographical world information... things like the calendar, some general economic facts (coins in international trade), moving into religion and the available deities. It's useful stuff to know, might be needed for some people to have handy, but can be in the middle of the book since you don't need it all the time.

Lastly, the Gazeteer... where's where in your world, and who's who once you get there. It's the kind of big information not every player needs, but which afficianados of your world will want to pore over.

The downside of a wiki, IMO, is that it's easier to miss things... important information that didn't happen to be linked on the page you looked at. But I'm also an old man.

[Yora]

FRCS seems to be pretty standard regarding layout, but I am not sure it's necessarily a really good one. I've seen other books do things differently, and so I am considering my other options.

Online wiki is quite useful too look up specific things, but I think not so good to get an introduction into a completely new setting. But since it's going to be free either way and it's all stuff I wrote myself, it won't be much trouble to simply copy the individual sections into a wiki as well.
But a book can have structure and explain each element in a sensible order.

The current index I have in mind looks like this:

Heroes/PCs
Races and Classes
Honor and Allegiance (Subsystems)
The Role of Heroes
The World
History
Calender
Beasts and Plants (overview)
Social structure (general)
Weapons and Technology
Religion
Magic
Spirits and Demons (overview)
The Peoples
[Individual entries]
Languages
Region Codex
[Individual entries]

Seems serviceable, but I am always looking for ways for improvement. Regarding each specific entry, I am thinking of something like in the first edition forgotten realms book. I separated peoples from regions, because most peoples are spread over multiple regions, and there's usually several groups present in any specific areas. As society is based much more on ethnic groups than states, that seems the practical choice.

[Palegreenpants]

That looks good. My limited editing experience has yeilded some possible changes. See what you think. Also, how many words/pages is this document?

Heroes/PCs
The Role of Heroes
Races and Classes
Honor and Allegiance (Subsystems)
The World
History
Social structure (general)
Weapons and Technology
Calender
Religion
Magic
Spirits and Demons (overview)
Beasts and Plants (overview)
The Peoples
[Individual entries]
Languages
Region Codex
[Individual entries]

[Yora]

I have no idea yet. I think I am aiming at about 100 pages.